Hello!

Adaptive radiation is basically when an organism develops and diversify from the old ancestral species due to the changes in the surrounding and environment and availability of new resources in the environment. In this way, the particular organism adapt to the new environment and diversify and evolve according to it.

Evolution of different species in a particular geographical area from a starting point that is ancestor and literally radiating in the adjoining areas is known as adaptive radiation.

Adaptive radiation is observed in the Darwin finches in galapago island,from ancestral larger seed eating birds different other species evolved which have changed their foraging pattern